Server-Side Request Forgery Vulnerability in Amazon AWS Systems Manager Agent

CVE-2026-89049

What is CVE-2026-89049?

CVE-2026-89049 is a server-side request forgery (SSRF) vulnerability found in the Amazon AWS Systems Manager Agent (SSM Agent) prior to version 3.3.4851.0. This agent is used primarily to manage AWS resources and automate operations across cloud environments. The vulnerability stems from improper validation of alternate representations of network addresses, specifically in the port forwarding feature. An authenticated remote user could exploit this flaw to circumvent a denylist meant to restrict access to link-local endpoints. This could potentially grant the attacker access to temporary IAM role credentials associated with a managed instance, thereby allowing them to execute actions using those permissions from an external location. If exploited, this vulnerability could facilitate unauthorized operations within an organization’s AWS infrastructure, leading to severe security breaches.

Potential impact of CVE-2026-89049

1. Unauthorized Access to Sensitive Resources: Attackers could gain access to IAM role credentials, allowing them to interact with AWS resources in unauthorized ways, potentially leading to data exposure or manipulation.

2. Escalation of Privileges: By exploiting the vulnerability, malicious actors could escalate their privileges within the AWS environment, giving them elevated permissions that could be used to impact other services or resources significantly.

3. Increased Risk of Data Breaches: The ability to access link-local endpoints and IAM roles increases the likelihood of data theft or leakage, profoundly affecting an organization’s integrity, confidentiality, and compliance with data protection regulations.

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